Habitat

L'Hoest's monkeys reside in montane tropical rainforests, including both primary and secondary forests. In secondary forests, they occupy the thick underbrush that grows where trees have fallen. L'Hoest's monkeys can be found at altitudes ranging from 900 to 2,500 m. The species is typically more terrestrial than other guenons. (Tolo, et al., 2008; "L’Hoest’s monkey (Cercopithecus lhoesti)", 2007)

Physical Description

L’Hoest’s monkeys are large, strikingly patterned monkeys with long limbs and a long tail. Females weigh approximately 3.5 kg, while males weigh approximately 6 kg. They are usually 31.7 to 68.6 cm in length, and tail length ranges from 48.3 to 99.1 cm. L'Hoest's monkeys are mostly covered in short dark gray fur, and they have a large chestnut saddle pattern on their back. There is also a distinctive large, conspicuous patch of white fluffy fur from the throat across the sides of the head almost to the ears. Their limbs and belly are black. Their face is mostly dark, with paler pinkish-white areas around the eyes and nose. Their long tail is medium gray, blacker near the tip, and is often held so the tip bends forward. Their eyes are bright orange. In males, the scrotum is bright blue in color, but otherwise both sexes are similar in coloration. L'Hoest's monkeys have narrow feet which aide running on the ground. They also have cheek pouches, used to carry food while foraging. ("Oregon Zoo Animals", 2005; Flannery, 2007)

Female L’Hoest's monkeys usually give birth every other year at the end of the dry season. On average, females L'Hoest's monkeys produce a single offspring after 5 months of gestation. Infants are born with their eyes open and fully covered in brown fur. Their fur darkens to adult coloration around 2 to 3 months of age. Young L'Hoest's monkeys nurse until mothers birth another offspring, but frequency of nursing considerably decreases after the first few months. On average, weaning occurs around 1 year of age. When males reach sexual maturity, they leave the group. ("BBC Science & Nature: Animals", 2008; "Oregon Zoo Animals", 2005)

Home Range

Little information is available regarding the home range of L'Hoest's monkeys.

Communication and Perception

L'Hoest's monkeys occassionally flee from predators while on the ground, which necessitates coordination, though the manner of this coordination is unknown. When females are ready to mate, they direct their hindquarters toward a male, know as presenting. L'Hoest's monkeys also utilize a variety of behaviors as a threat display. Staring involves fixing the eyes on a subject, raising the eyebrows, stretching the facial skin, and moving the ears back. Often, they open their mouth but do not display their teeth. Additionally, they may engage in head-bobbing, which often occurs with staring with an open mouth, and is also a threat display. (Flannery, 2007; "L’Hoest’s monkey (Cercopithecus lhoesti)", 2007)

Food Habits

The diet of L'Hoest's monkeys consists mainly of fruits, leaves, and invertebrates. Invertebrates typically constitute a little less than half of the diet, while fruits and plant materials make up over 50%. However, in some locations, the dietary percentage of invertebrates is as low as 9%. L’Hoest’s monkeys usually forage for mushrooms, terrestrial herbs, and arthropods in the lower strata of the forest and search the upper strata for small fruits, buds, flowers, young leaves (which have more protein than mature leaves), and herbaceous stems. They often look for arthropods in shallow streams, fallen leaves, trunks, and branches of the forests. L'Hoest's monkeys favor fruits of Myrianthus arboreus, Polycias fulva, Musanga leo-errerae, and Ficus spp. Some invertebrates in their diet include insects, earthworms, spiders, ants, and grasshoppers. L'Hoest's monkeys also have cheek pouches, in which they carry food while foraging. (Flannery, 2007; Tolo, et al., 2008)

Ecosystem Roles

Due to their semi-frugivorous diet, L’Hoest’s monkeys play a role in seed dispersal. Members of this species are known to host two types of gastrointestinal worm parasites, Strongyloides fulleborni and a species of Trichurus. (Gillespie, et al., 2004)

Conservation Status

L'Hoest's monkeys are considered vulnerable by the ICUN Red List and endangered by the US Federal List. Populations are decreasing because of deforestation due to agricultural expansion as well as hunting. L'Hoest's monkeys were at one point listed in Appendix II by The Convention on International Trade in Endangered Species (CITES), which means international trade of this species is monitored. However, hunting of this species for bushmeat still occurs. L'Hoest's monkeys are most vulnerable to snares and shotgun hunting. (Hart, et al., 2008; "L’Hoest’s monkey (Cercopithecus lhoesti)", 2007)

Contributors

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

diurnal

active during the day, 2. lasting for one day.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.